The Hunter recorded its third, fourth and fifth cases on Monday, two of them linked to a woman in her 60s who had been attending the Mater oncology unit as an outpatient over nine days up to March 12.

Hunter New England Health's director of health protection, Dr David Durrheim, spoke to the Newcastle Herald about the virus and what the community can do to limit its spread.

What can the Hunter expect in the coming days and weeks?

"What we are certainly hoping to see in Australia and Hunter New England is that the measures that are being taken to restrict the spread of the virus, both through early detection of cases, the tracking of close contacts ... and now the social distancing measures that are coming into place will slow the spread of this virus and really limit its impacts.

"What we want to see in Hunter New England is what we've seen in a couple of really high-performing countries in our region.

"I think we could look at Singapore and Hong Kong, who've done a great job in limiting the spread. And we don't want to see what we've seen in some countries in Europe."

Case numbers seem to be growing rapidly in Australia in the past few days. Is that a worry?

"The increase in cases, and particularly the increase in the number of cases that haven't got a clear source of transmission, has been the underlying consideration in promoting social distancing.

"When every individual case that came in could be linked to an individual travel event, I think that it was appropriate to manage individuals and their close contacts.

"But at this stage it's quite appropriate to go to the next stage of community transmission slowing."

Why are we any different to a wealthy, modern country like Germany, which is adding 700 new cases a day?

"I think what we have in Australia that's unique is that because we are a very large island we have a much greater opportunity than Germany, where there are constant flows of people through all of those European borders, until recently with a few of those closing borders.

"I think we should see Europe as a single country in some respects in terms of the way that people flow."

Is the John Hunter Hospital equipped to deal with a surge in cases?

"All of the health services across Hunter New England Health district have pandemic plans, which is highly appropriate, and as necessary they step those up.

"All of the emergency departments have been kept abreast of all the developments, and screening criteria, and have all been ordered to make sure they are ready to respond.

"We've seen the stepping up of a coronavirus screening centre at the John Hunter campus, and, if necessary, those could be replicated at other services as well.

"Obviously, we're going to throw everything at it we can to slow down the spread of this virus."

What about equipment at the hospital?

"The chief health officer is working with the CEs of all the local health districts to make sure that they can surge, and that's both for critical care as well as for emergency departments.

"Some of that is more equipment, but sometimes it is the redeployment of equipment and other resources.

"That's how health departments generally respond, with the prioritisation of the equipment and human resources to the greatest need."

Should the Knights game have gone ahead on Saturday with fans present?

"It's a really interesting situation.

"Obviously, we from a public health point of view welcome the fact that large events have actually been curtailed because it will limit the spread of this virus in Australia.

"The timing of that obviously being on Monday means certain large-scale events have occurred.

"What I'm really hoping is that anybody who has had either fever or respiratory illness will have done the right thing and actually not attended any of those mass gatherings, whether it's the Knights game or any other large community events."

Australians were seemingly encouraged to attend sports events last weekend. Was that the right message?

"The timing is made by people well above my pay grade, and obviously there's criticality in being able to perform the logistics of switching off things, so those factors would have been taken into consideration.

"I think what we're going to find is that Australians are going to realise that we all have to make a contribution to ramp up our respiratory hygiene and we're going to have to stay at home when we're ill and not spread it in the community.

"There's a lot of very practical things that Australians can do to limit the spread of this virus, and one of those is going to be how we interact and try news ways of interacting with people or staying a safe distance from others.

"Because the virus is largely droplet-spread, if one could keep two metres away from somebody, the likelihood of them getting infected is almost nothing.

"Of course, we don't want to have people coughing or sneezing on their hands and then spreading that around. A key to preventing further spread is absolutely meticulous hand hygiene."

Can you catch the virus more than once?

"That's a really great question. We know there are two strains of the virus which are slightly different.

"We do believe that the virus probably only emerged in November, from the genetic analysis, before being detected in humans in China in December of last year.

"Already we can see there are two slightly different strains of the virus. They share almost all of their genetic material, though, and that's really quite reassuring in that if a vaccine is developed it will probably provide great protection against both strains.

"We expect this with RNA [ribonucleic acid] viruses. They do slowly gather mutations. This one doesn't seem to be different.

"The issue about people being re-infected, it's very unlikely. If a person mounts some immune response, and we even see this with other similar respiratory RNA viruses, it's generally they are protected at least partially for a period of time. It's usually for a full season.

"What might have been happening is that people might have been prematurely told that they were free of the virus and been retested before they were really cleared.

"That may have been a contributing factor to that phenomenon, but it is on a very small scale as well."

Should schools and offices shut down?

"I think decisions will be made on schools and workplaces in the future. Clearly, if we find that schools are major transmission contributors, then I think decisions will be made about schools.

"The good news that we're seeing is that children seem to get generally a much milder form of the illness with this virus infection.

"Clearly, into the future as we see more community-wide transmission there'll be considerations about school closures, university closures."

RELATED NEWS

Where are we heading in terms of overall numbers of confirmed cases and deaths?

"I think it's impossible to say at this stage.

"The chief health officer in NSW, Dr Kerry Chant, has already been quoted as saying that up to 20 per cent of the NSW population may be infected in this first wave.

"I think the critical thing is that with that as a worst-case scenario we really need to make every effort we can to slow the community spread.

"Often with pandemics is there is some seasonality, especially respiratory pathogens.

"They appear to, and this has always been the case with influenzas, they spread and survive much better during the winter months.

"Whether that's going to be the case with COVID-19, it's too early to tell. We'll learn that from the northern hemisphere experience, because obviously they're going to move out of their winter into spring and summer and we'll then be able to better predict what might be the occurrence in the southern hemisphere.

"As we've seen with the flu, then when they go back into winter there's a second pandemic, but that's specific to flu and we don't really know what the pattern will be with COVID-19.

"What we have found from experience overseas is that most of the transmission is from people that are symptomatic.

"There's very little transmission from people who are asymptomatic, and that assists us in actually detecting what the likely source of infection was and if there's anyone else who might be exposed."

We have removed our paywall from online stories about the coronavirus. This is a rapidly changing situation and we need to make sure our readers are as informed as possible.